Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754297AbaA0Wbu (ORCPT ); Mon, 27 Jan 2014 17:31:50 -0500 Received: from mail-pd0-f175.google.com ([209.85.192.175]:50819 "EHLO mail-pd0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753722AbaA0Wbr (ORCPT ); Mon, 27 Jan 2014 17:31:47 -0500 MIME-Version: 1.0 In-Reply-To: References: <1390795167-6677-1-git-send-email-jcmvbkbc@gmail.com> <1390795167-6677-2-git-send-email-jcmvbkbc@gmail.com> <1390817904.2735.127.camel@deadeye.wl.decadent.org.uk> <52E6868C.3070401@gmail.com> From: Florian Fainelli Date: Mon, 27 Jan 2014 14:31:07 -0800 Message-ID: Subject: Re: [PATCH 1/3] net: ethoc: don't advertise gigabit speed on attached PHY To: Max Filippov Cc: Ben Hutchings , "linux-xtensa@linux-xtensa.org" , netdev , "devicetree@vger.kernel.org" , LKML , Chris Zankel , Marc Gauthier , "David S. Miller" , Grant Likely , Rob Herring Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (fixing Rob's email) 2014-01-27 Max Filippov : > On Mon, Jan 27, 2014 at 11:36 PM, Florian Fainelli wrote: >> 2014-01-27 Max Filippov : >>> On Mon, Jan 27, 2014 at 2:18 PM, Ben Hutchings wrote: >>>> On Mon, 2014-01-27 at 07:59 +0400, Max Filippov wrote: >>>>> OpenCores 10/100 Mbps MAC does not support speeds above 100 Mbps, but does >>>>> not disable advertisement when PHY supports them. This results in >>>>> non-functioning network when the MAC is connected to a gigabit PHY connected >>>>> to a gigabit switch. >>>>> >>>>> The fix is to disable gigabit speed advertisement on attached PHY >>>>> unconditionally. >>>>> >>>>> Signed-off-by: Max Filippov >>>>> --- >>>>> drivers/net/ethernet/ethoc.c | 2 ++ >>>>> 1 file changed, 2 insertions(+) >>>>> >>>>> diff --git a/drivers/net/ethernet/ethoc.c b/drivers/net/ethernet/ethoc.c >>>>> index 4de8cfd..0aa1a05 100644 >>>>> --- a/drivers/net/ethernet/ethoc.c >>>>> +++ b/drivers/net/ethernet/ethoc.c >>>>> @@ -712,6 +712,8 @@ static int ethoc_open(struct net_device *dev) >>>>> netif_start_queue(dev); >>>>> } >>>>> >>>>> + priv->phy->advertising &= ~(ADVERTISED_1000baseT_Full | >>>>> + ADVERTISED_1000baseT_Half); >>>>> phy_start(priv->phy); >>>>> napi_enable(&priv->napi); >>>>> >>>> >>>> This is not sufficient to disable gigabit speeds; the supported mask >>>> should also be limited. And it should be done even before the net >>> >>> I tried that, but when I also limit supported mask the phy driver doesn't >>> touch gigabit advertising register int the genphy_config_advert at all. >>> That's probably right for ethtool interface, but ethoc doesn't support >>> ethtool. >> >> This is not right for libphy either, phydev->supported must reflect >> that you support Gigabit or not. > > I'm sorry, does that mean that I must not touch phydev->supported, > or that I must update it too and somehow fix genphy_config_advert? What I meant is that your driver has to set both phydev->advertising and phydev->supported. genphy_config_advert() is doing phdev->advertising &= phydev->supported, leaving phydev->supported to something more restrictive will produce unexpected results. This is also important if phy_driver::config_aneg() is not using the generic implementation and directly uses/modifies phydev->advertising and phydev->supported. It seems like there is room for improvements in that area regardless of how we access things. For instance, specifying the PHY interface mode (MII, GMII etc...) should already provide a hint of what phydev->supported should look like. You cannot do Gigabit with MII for instance. > >> Since ethoc supports libphy, there really is no reason not to >> implement the ethtool_{get,set}_settings callbacks using >> phy_mii_ioctl(). > > Ok, I'll add that. > >>>> device is registered. >>>> >>>> Rather than poking into the phy_device structure directly from this >>>> driver, I think you should add a function in phylib for this purpose. >> >> All drivers are currently modifying phydev->advertising and >> phydev->supported directly, most of them do it correctly as far as I >> checked. It does make some sense to add a helper function though. > > [...] > >>> diff --git a/include/linux/phy.h b/include/linux/phy.h >>> index 48a4dc3..0282a8d 100644 >>> --- a/include/linux/phy.h >>> +++ b/include/linux/phy.h >>> @@ -559,6 +559,11 @@ static inline int phy_read_status(struct phy_device *phydev) { >>> return phydev->drv->read_status(phydev); >>> } >>> >>> +static inline void phy_update_adv(struct phy_device *phydev, u32 mask, u32 set) >>> +{ >>> + phydev->advertising = (phydev->advertising & mask) | set; >>> +} >>> + >> >> This should be a preliminary patch to this patchset, so you first >> introduce the function, then use it in the driver, but the idea looks >> good. There is room for updating quite some drivers out there since >> those used to modify phydev->advertising and phydev->supported >> directly without using an accessor. > > What about those that do something like this: > > phydev->advertising = phydev->supported; > > leave them as is, or provide read accessor for phydev->supported? Those should be just fine since genphy_config_advert() does phydev->advertising &= phydev->supported, so the end result will be identical. You mean a write accessor instead of a read accessor? -- Florian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/